The Radeon X800 XT outperforms the GeForce 6800 Ultra in Quake 3: Arena at every resolution, regardless of whether sound is on or off. Surprisingly, even the Radeon 9600 XT and 9800 Pro top the GeForce 6800 Ultra at 640x480. This may be due in part to its slower core clock and/or ATI's more efficient drivers.

In Unreal Tournament 2004, the GeForce 6800 Ultra edges out the Radeon X800 XT. But once full scene anti-aliasing and anisotropic filtering are enabled, the tables are completely turned. The GeForce 6800 Ultra's performance drops off so severely after 800x600, that it finds the "lowly" Radeon 9800 Pro nipping at its heels. The Radeon X800 XT enjoys a comfortable 75% lead at high resolution. Forty-seven frames per second is certainly a playable framerate, but when playing online against human opponents, the difference is magnified.